docs: def _update_from_vcs(self, output):
          "Update state based on the VCS state e.g the output of git describe"
          split = output[1:].split('-')
          dot_split = split[0].split('.')
          for prefix in ['a','b','rc']:
              if prefix in dot_split[-1]:
                  prefix_split = dot_split[-1].split(prefix)
                  self._prerelease = prefix + prefix_split[-1]
                  dot_split[-1] = prefix_split[0]
  
  
          self._release = tuple(int(el) for el in dot_split)
          self._commit_count = int(split[1])
  
          self._commit = str(split[2][1:]) # Strip out 'g' prefix ('g'=>'git')
  
          self._dirty = (split[-1]=='dirty')
          return self